| This dissertation describes the first investigation of EM properties of 40–90 nm wide Al and Al-Cu lines. Experiments revealed several previously unknown EM behaviors of nanometer lines. One is a broad distribution of lifetimes. Weak-link segments in the lines were believed to be responsible for early failures, while the long lifetimes were due to the stability of the bamboo structure. Those lines that survived early failures exhibited morphological changes including bump formation and local narrowing. Bumps in some cases were huge compared to the line dimensions.; More details and dynamic information were obtained in an in situ study. In Al-Cu samples, narrowing of line segments occurred in all lines on the downwind side, and sequences of bump growth and shrinkage within groups indicated interactions among nearby bumps.{09}Bumps in pure Al developed earlier and became larger than in Al-Cu lines. Bumps in both Al-Cu and pure Al samples tended to curl upwind (toward the cathode); the data were consistent with material transport dominated by diffusion along the interfaces between Al and its surrounding dielectric. |
